15 results about "Alpha helix" patented technology

The invention discloses judgment and optimization of key amino acid sites for controlling sesquiterpene synthesis, and determines amino acid residues lysine or arginine or glutamine related to sesquiterpene synthesis for point mutation and combined mutation of various plant sesquiterpene synthase. Lysine or arginine or glutamine is located in a cavity among 5-10 amino acids in front of the first long alpha helix at the N end, alpha helixes (also the longest alpha helix in the protein) communicating the N end and the C end of the protein and the last 1-7 amino acids at the C end at the site. The method for determining the key amino acid can be used for efficiently screening the sesquiterpene synthase with activity, and the optimization of the amino acid of the key residue can be used for guiding the transformation of the high-yield sesquiterpene synthase for industrial production. The invention has important application value and economic benefit in the fields of biological synthase identification of sesquiterpenoids, biosynthesis of drugs, fermentation production of spices, synthesis of industrial raw materials and the like.

The application discloses an N-terminal protection sequence for improving stability of 7beta-hydroxysteroid dehydrogenase and a high-efficiency preparation method of the fusion protein, and belongs to the technical field of biology.The N-terminal protection sequence for improving the stability of 7beta-HSDH is designed and synthesized, the protection sequence is composed of 45 amino acids, the N-terminal alpha helix of the original 7beta-HSDH is embedded by a backfolding structure, and the stability of the 7beta-HSDH can be effectively improved.The half-life of the enzyme mutant N45-7beta-HSDH with the protection sequence is prolonged by 2.8 times compared with that of the original 7beta-HSDH under the catalytic condition of pH 8.0 and 30 DEG C.The enzyme consumption for generating UDCA from 7-KLCA by using the above N45-7beta-HSDH is reduced by 45.5%, the molar conversion rate is as high as 99.41%, the production cost is greatly reduced, and the method has actual industrial production value.

The present disclosure generally relates to a CEA-binding polypeptide comprising at least one alpha helix and a CEA-binding motif, wherein the CEA-binding motif is located on the at least one alpha helix and comprises the amino acid sequence XaXbXcXdXe (SEQ ID NO:1), wherein Xa is F or W; Xb is W; Xc, and Xd are individually selected from any amino acid; and Xe is W or Y. The present disclosure also relates to a fusion protein or conjugate comprising the CEA-binding polypeptide, and to its use in a method of treatment, as well as for vitro diagnosis of the presence and / or level of CEA in a sample.

There is provided a polynucleotide-modifying enzyme with a functional nuclease domain and a display domain. The functional nuclease domain comprises a nuclease catalytic pocket. The display domain comprises a peptidic recognition sequence of from 3 to 20 amino acids in length, in a loop, an alpha helix or an extension off the end of the alpha helix that is positioned on an external surface of the polynucleotide-modifying enzyme. The peptidic recognition sequence recognizes a target cell receptor of a target cell to allow cell internalization of the polynucleotide-modifying enzyme in said target cell.

The invention relates to the technical field of agricultural biology, in particular to an alpha spiral mutant of granulysin with improved antibacterial activity and application of the alpha spiral mutant. The amino acid sequence of the alpha spiral mutant peptide of granulysin with improved antibacterial activity is as shown in SEQ ID No: 2. According to the present invention, the antibacterial activity of the granulysin mutant on different bacteria such as gram-negative bacteria salmonella typhimurium, escherichia coli and salmonella pullorum is enhanced;

The invention relates to the technical field of biological medicines, and discloses a dual-targeting adhesion-immune activation fusion peptide, an anti-escherichia coli O157: H7 monoclonal antibody GS2-D3, curcumin nanoparticles and a probiotic composition composed of the curcumin nanoparticles. The fusion peptide solves structural conflicts by inserting an alpha helix stable domain composed of four EAAAK repetitive units and a GPGP flexible buffer domain, a targeting domain YIGSR and an MUC2 binding domain PTPSFTT are introduced to improve the targeting efficiency, and the enzymolysis resistance is enhanced through site mutation; the monoclonal antibody GS2-D3 can be used for specifically recognizing escherichia coli O157: H7; the curcumin nanoparticles improve the stability and bioavailability of curcumin. The probiotic composition contains the components, has the effects of efficient colonization, bacteriostasis, inflammation resistance and intestinal flora regulation, can effectively treat intestinal inflammation, is low in cost and high in safety, and has good clinical transformation potential.

The present application relates to the technical field of recombinant protein, and particularly relates to screening of a recombinant keratin K35 mutant, construction of a Pichia pastoris expression vector and protein expression. The recombinant keratin K35M has an amino acid sequence as shown in SEQ ID NO. 2. The wild-type keratin K35 is subjected to sequence optimization through site-directed mutation, and the mutation site is determined as M237L / S243N, and part of the amino acids at the N-terminal and C-terminal are removed, and the central alpha helix rod-shaped region is reserved. The binding capacity of the protein to calcium ions is improved through the above modification, and the stability, functional activity and expression level of the protein itself are improved, which lays a molecular foundation for the application of the protein in tissue repair, oral cavity repair and the like. The technical scheme can solve the problems of the existing recombinant keratin K35, such as insufficient calcium chelation capacity, low recombinant expression level and disadvantages of a prokaryotic expression system, and significantly improves the application value and industrialization potential of the recombinant keratin.

This invention discloses a method for rapidly screening highly efficient α-helical antimicrobial peptides and its application. The method includes extracting hydrophobic cluster scores HCS3_HF and / or HCS4_HF from the peptide sequences to be screened, and screening the peptide sequences based on the values ​​of these features. Using known low-MIC α-helical antimicrobial peptides as multi-centroid references, precise selection of candidate peptides is achieved through feature value ranges. This invention constructs a screening system based on the structure-activity relationship of the synergistic effect of hydrophobic clusters at positions i+3 and i+4 of the hydrophobic surface. This system can efficiently identify α-helical antimicrobial peptides with low minimum inhibitory activity from a vast sequence space without relying on large-scale training data, significantly shortening the antimicrobial peptide development cycle.

The invention belongs to the technical field of biological medicines, and particularly relates to a stapled strategy modified polypeptide and application thereof. The invention designs and synthesizes a stripled-modified polypeptide containing a permeable membrane peptide and an alpha spiral fragment and a polypeptide carrier. The polypeptide and the polypeptide carrier provided by the invention have good delivery capacity, stability and biocompatibility, are relatively low in toxicity, and can effectively improve the problems of cell delivery of nucleic acid or drugs, endosome escape and the like. After stapled modification, the stability of the polypeptide carrier is greatly improved, and the polypeptide carrier has the potential of being developed as a delivery carrier.

The present application relates to the field of biotechnology, in particular to a pair of mutually recognizing and combining alpha helix peptides and application thereof. The alpha helix peptide 1 has an amino acid sequence as shown in SEQ ID No. 1, and the alpha helix peptide 2 has an amino acid sequence as shown in SEQ ID No. 2. The cells are combined with each other by a pair of mutually recognizing and combining alpha helix peptides, so that the cells are arranged in a desired manner. The suitable material concentration and action time are verified; the formed cell group morphology is observed by various microscopes; two kinds of models are successfully constructed; and the improvement of cell function by adding DPH material is verified.

The application discloses a polypeptide as a NEK7-NLRP3 inhibitor and a use thereof. The polypeptide is simple in preparation method and novel in structure; the polypeptide has no obvious toxicity to THP-1 cells; the polypeptide can keep a good alpha helix configuration in an amphiphilic environment; the polypeptide is derived from an alpha helix binding area of NEK7 protein and NLRP3 protein, has high affinity with NLRP3 protein; the polypeptide can interfere with the oligomerization of NLRP3 protein, inhibit the activation of NLRP3 inflammasome, significantly reduce the maturation and secretion of IL-1beta, and then improve the inflammatory microenvironment and reduce pyroptosis, and has good anti-inflammatory activity; the application also relates to a preparation method of the polypeptide, a pharmaceutical combination containing the polypeptide, and a use of the polypeptide alone or in combination with other compounds for preventing or treating inflammation-related diseases.

The invention relates to an insecticidal protein Cif and an expression vector and application thereof. The three-dimensional structure of the insecticidal protein Cof comprises two structural domains, and the structural domain I is composed of alpha helixes and located at the 16-187 sites of an amino acid sequence; the connecting domain consists of an alpha helix and three beta folds, and is positioned at the 188-285 sites of the amino acid sequence; and the structural domain II is formed by beta folding and is located at 286-426 sites of the amino acid sequence. The insecticidal protein Cof is a novel non-Cry protein, and can be effectively expressed in bacillus thuringiensis after sequence optimization. Experiments prove that the P5014 can guide expression of the Cif protein and has a poisoning effect on spodoptera frugiperda.

The application discloses a method for rapidly screening high-efficiency alpha helix antibacterial peptides and application thereof, and the method comprises the following steps: extracting hydrophobic cluster set scores HCS3_HF and / or HCS4_HF of a peptide sequence to be screened, and screening the peptide sequence according to the value of the characteristic. The known alpha helix antibacterial peptide with low MIC is used as a multi-centroid reference, and the precise selection of the candidate peptide is realized through the characteristic value interval. The screening system is constructed based on the synergistic effect of the hydrophobic surface i+3 and i+4 hydrophobic cluster set, the alpha helix antibacterial peptide with low minimum inhibitory activity can be efficiently locked from a huge sequence space without relying on large-scale training data, and the research and development cycle of the antibacterial peptide is significantly shortened.

The invention relates to an insecticidal protein Rhc as well as an expression vector and application thereof. The three-dimensional structure of the insecticidal protein Rhc comprises two structural domains, and the structural domain I is composed of a plurality of alpha helixes and located at the 6th-175th site of an amino acid sequence; the connecting domain consists of an alpha helix and three anti-parallel beta folds, and is positioned at 176-241 sites of an amino acid sequence; and the structural domain II takes beta folding as a main body and is located at 262-436 sites of the amino acid sequence. The insecticidal protein Rhc is a novel protein, and under the background of a delta cdsR mutant, the promoter P5014 can effectively guide the expression of the Rhc protein; a biological activity test shows that the median lethal concentration (LC50) of Rhc protein expressed under the guidance of P5014 in the delta cdsR mutant to newly hatched larvae of melotidax aeda is 233 [mu] g / mL.

The invention relates to the technical field of agricultural biology, in particular to an antibacterial peptide pig NK lysin mutant and application thereof. The amino acid of each alpha helix of the antibacterial peptide, especially the composition and position of basic amino acid and hydrophobic amino acid, is subjected to combined mutation, so that the antibacterial peptide with an enhanced antibacterial function is screened. The antibacterial activity of the pig NK lysin mutant disclosed by the invention on different bacteria, such as staphylococcus aureus, salmonella typhimurium, escherichia coli and salmonella pullorum, is enhanced.